title: Trends and significance of VRE colonization in the ICU: a meta-analysis of published studies.
abstract: BACKGROUND
  The burden and significance of vancomycin-resistant enterococci (VRE) colonization in the ICU is not clearly understood.
  
  
  METHODS
  We searched PubMed and EMBASE up to May 2013 for studies reporting the prevalence of VRE upon admission to the ICU and performed a meta-analysis to assess rates and trends of VRE colonization. We calculated the prevalence of VRE on admission and the acquisition (colonization and/or infection) rates to estimate time trends and the impact of colonization on ensuing VRE infections.
  
  
  RESULTS
  Across 37 studies (62,959 patients at risk), the estimated prevalence of VRE on admission to the ICU was 8.8% (7.1-10.6). Estimates were more consistent when cultures were obtained within 24 hours from admission. The VRE acquisition rate was 8.8% (95% CI 6.9-11.0) across 26 evaluable studies (35,364 patients at risk). Across US studies, VRE acquisition rate was 10.2% (95% CI 7.7-13.0) and demonstrated significant decline in annual trends. We used the US estimate of colonization on admission [12.3% (10.5-14.3)] to evaluate the impact of VRE colonization on admission in overall VRE prevalence. We demonstrated that VRE colonization on admission is a major determinant of the overall VRE burden in the ICU. Importantly, among colonized patients (including admitted and/or acquired cases) the VRE infection rates vary widely from 0-45% (with the risk of VRE bacteremia being reported from 0-16%) and <2% among those without a proven colonization.
  
  
  CONCLUSIONS
  In summary, up to 10.6% of patients admitted in the ICU are colonized with VRE on admission and a similar percentage will acquire VRE during their ICU stay. Importantly, colonization on admission is a major determinant of VRE dynamics in the ICU and the risk of VRE-related infections is close related to colonization.
authors.affiliation: Infectious Diseases Division, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America.
authors.forename: Panayiotis D
authors.initials: PD
authors.lastname: Ziakas
authors.forename: Rachana
authors.initials: R
authors.lastname: Thapa
authors.forename: Louis B
authors.initials: LB
authors.lastname: Rice
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Mylonakis
mesh_terms: D001424:Bacterial Infections / Q000453:epidemiology*; D003428:Cross Infection / Q000453:epidemiology*; D016983:Enterococcus; D006760:Hospitalization; D006801:Humans; D007362:Intensive Care Units; D015995:Prevalence; D014640:Vancomycin / Q000009:adverse effects*; D020713:Vancomycin Resistance / Q000502:physiology*
chemical_list: D014640:Vancomycin